Continuing investigations on this project are geared primarily to the (1) exploration of the prenatal antecedents of human postnatal dental variability, and (2) correlation of such dental variabilities with recognizable patterns of development in contiguous facial regions and in body regions geographically removed from the dentofacial area, e.g. wrist and hand. The former problem has been approached by "morphologic staging "individual deciduous and permanent tooth germs as seen in serial, histologic sections from over 600 human abortuses representing key stages of dental development. In addition to identifying patterns or progressive dental morphogenesis as related to some measure of age, other parameters include sex, race, karyotypic information (whenever available) as they bear on such considerations of dental arch assymetries, sequence polymorphisms, and isomere, opponent, and adjacent tooth correlations. The latter aim, which puts dental development into the context of total body development, is being approached by correlating the recognizable patterns of early tooth development with patterns identified for other body regions, including hand-wrist, eye, heart. This project stressing multi-correlations from both within the dental region and between the dental region and other regions has another unique feature in that morphologic data is, whenever possible, correlated with histories of the pregnancy and family from which the abortus was derived.